I was having the same problem as you are. I installed GitHub before and it worked fine. I uninstalled it then trying to reinstall it but nothing happens whenever I click the GitHub icon.

What helped me solve my problem was to delete the GitHub folders left behind from AppData\Local and Roaming folders. Then I reinstalled GitHub and now it works.

• From the Windows Start menu choose Run (Or Windows Key + R)
• Enter the following, depending on your version of Windows, then click the OK button:

On Windows Vista or higher, delete the %LocalAppData%\GitHub and the %AppData%\GitHub directories.

On Windows XP, delete the %USERPROFILE%\Local Settings\Application Data\GitHub directory.

HTH.

Source: Uninstalling GitHub for Windows

I was having the same problem as you had. I installed GitHub before, and it worked fine. I uninstalled it then trying to reinstall it, but nothing happens whenever I click the GitHub icon.

Deleting the GitHub folders left behind from AppData\Local and Roaming folders helped me solve my problem. Then I reinstalled GitHub and now it works.

• From the Windows Start menu, choose Run (or Windows Key + R)
• Enter the following, depending on your version of Windows, and then click the OK button:

On Windows Vista or higher, delete the %LocalAppData%\GitHub and the %AppData%\GitHub directories.

On Windows XP, delete the %USERPROFILE%\Local Settings\Application Data\GitHub directory.

Source: Uninstalling GitHub for Windows